Antioxidant activity and phenolic content of different extracts of Gentiana cruciata L
Gentiana cruciata L. is a perennial plant belonging to the genus Gentiana (fam. Gentianaceae) . Gentiana species are widely used throughout the world as potential stomachic and hepatoprotective agents . G. cruciata is used in the traditional medicine for loss of appetite, as a stomachic as well as component in preparations showing beneficial effects in gall and liver diseases . The aim of this study was to evaluate the antioxidant and radical-scavenging activities of methanol extract, chloroform, ethyl acetate and n-butanol fractions obtained from the methanol extract of aerial part of G. cruciata. Amounts of total phenols and flavonoids were also determined. The total phenolics contents in the fractions and extract were determined as gallic acid equivalent (GA) using Folin-Ciocalteu's reagent, while the spectrophotometric method with aluminium chloride was used for the determination of total flavonoids. The total amount of flavonoids was calculated as the rutin equivalent (RU).The extracts were investigated for antioxidant capacity using two different assays: DPPH assay and inhibitory activity toward lipid peroxidation. The highest content of total phenols (109.8mg GA/g) and flavonoids (110.9mg RU/g) was determined in the n-butanol fraction. The most effective DPPH radical scavenger was n-butanol fraction (IC50=114.7µg/mL), while the methanol extract showed the highest inhibitory activity toward lipid peroxidation (IC50=69.9µg/mL). The results show a significant antioxidant activity of the investigated extracts compared to referent antioxidant compounds, such as butylated hydroxytoluene (BHT), ascorbic acid (AA), gallic acid (GA) and α-tocopherol.
Keywords: Gentiana cruciata, antioxidant activity, phenolic content
Acknowledgement: This work was supported by the Ministry of Science and Technological Development of the Republic of Serbia (project No. III 43004).
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